Selective two-speed hand tool



Dec. 31, 1957 M. F. STAHL SELECTIVE TWO-SPEED HAND TOOL 2 Sheets-Sheet 1 Filed July 27, 1956 x m\ m Q 9 w/ M m. a mm fl I P n !O\ Iv .|H M w an M Qmw R N Dec. 31, 1957 M. F. STAHL 2,817,988

' SELECTIVE TWO-SPEED HAND TOOL Filed July 27. 1956 .2 Sheets-Sheet 2 INVENTOR. MILTON E STAHL 2,817,988 Patented Dec. 31, 1957 ice 2,817,988 7 SELECTIVE TWO-SPEED HAND TOOL Milton F. Stahl, Tallmadge, Ohio Application July 27, 1956, Serial No. 600,425 Claims. (Cl. 8173) This invention relates to multiple speed wrenches, and in particular relates to a two-speed wrench of the type operated with a certain relatively great force at given relatively low speed for initially loosening a nut on a bolt, for example, and then operating the same with less force but at a higher speed in the interest of saving time.

This application is a continuation in part of application Serial No. 457,891, filed September 23, 1954, now Patent No. 2,761,341, issued September 4, 1956.

One object of the invention is to provide a speed wrench of the type described which is automatically adjustable from one speed to another simply by changing the manual pressure applied to the wrench in the direction of work being turned thereby.

Another object of the invention is to provide a simple, compact, and easy to operate tool for the purposes described.

Other objects of the invention will be manifest from the following brief description and the accompanying drawings.

Of the accompanying drawings:

Figure 1 is a front view, partly broken away, of a speed wrench embodying the features of the invention, with the parts thereof in position for high speed operation of the wrench.

Figure 2 is an enlarged fragmentary vertical cross-.

section of the right-hand end of the wrench as viewed in Figure 1, illustrating a clutch mechanism in the disengaged condition of Figure 1 for said high speed operation of the wrench.

Figure 3 is an enlarged end view of the hand-grip at the left of Figure 1.

Figure 4 is an enlarged fragmentary view of the lefthand end of the wrench as viewed in Figure 1, but one segment of a hollow hand-grip being removed to show gear means therein in non-meshing relation for low speed operation of the wrench.

Figure 5 is an enlarged front elevation of the righthand end of the wrench as viewed in Figure 1, with the clutch mechanism in engaged condition.

Figure 6 is a view similar to Figure 4, and illustrates a modified form of the invention.

Figure 7 is an end view taken from the left of Figure 6, but with the dome-shaped cap removed.

Referring particularly to Figures 1 to 3, there is illustrated a two-speed wrench, embodying the features of theinvention, in condition for high speed operation of the same. The numeral 10 designates a curved member having a U-shaped central hand-grip portion 11 and curvately connected straight end portions 12 and 13 which extend in outwardly opposite directions to be on a common axis. A handle 14 is suitably rotatably received on the central hand-grip portion 11. Member 10 may be of hollow rigid material, such as steel tubing, and has rotatably and axially slidably received in passageway 16 thereof a length of flexible but inextensiblematerial, such as steel cable 17.

On the straight end portion 13 of member 10 may be clutch means 18, including a clutch part 20 fixed on the end portion 13 and a clutch part 21 in the form of a sleeve, rotatably and slidably received on said end portion 13 outwardly of the fixed clutch part, to be axially shiftable toward and from clutching engagement of teeth 22 and 23 on the clutch parts 20 and 21, respectively (see Figures 1, 2 and 5). Affixed in the outer end of sleeve 21 as by means of a pin 19 extended through the sleeve, may be a work-turning part 24, having an outwardly projecting squared end 25 for ready reception of a wrench socket (not shown) of known type, the inner end of said part 24 having a metal bushing 26 secured therein by said pin 19, and the bushing 26 in turn having the corresponding end 27 of cable 17 attached thereto, as by silver soldering. For maintaining the clutch parts 20 and 21 normally disengaged, as shown in Figures 1 and 2, a compression spring 28 is yieldingly engaged between opposing ends of end portion 13 and work-turning part 24.

A hollow hand-grip or knob 31 may have a boss 32 provided with a bore 33, in which the straight portion 12 of tubular member 10 is rotatably received. For retaining the hand-grip 31 against axial movement on said end portion 12, an annular recess 34 extending radially outwardly from bore 33, is adapted to receive a complementally shaped rib 35 which is integral with member 10. To facilitate assembly, hand-grip 31 is made with two halves 36 and 37, secured together at the boss 32, as by means of screws 38, 38, and further by a bevel gear 39 fastened, as by means of screws 41, to a flat outer wall 42 of the hand-grip (see Figure 3). Bevel gear 39 is axially aligned with the straight and portions 12 and 13, and the end portion 12 has an integral ex tension 42, at a substantial angle to the axis through said end portions, and a bevel pinion 43 affixed on the corresponding end of cable 17 is normally in mesh with gear 39 when the clutch 16 is disengaged, as shown in Figures 1 and 2. Thus, upon turning the member 10 about the aforementioned axis in known manner, with the bevel gears 39 and 43 meshed and the clutch means 18 disengaged, the work-turning part or member 24 is operable at relatively high speed. Conversely, while similarly turning member 10, the work-turning member 24 is operable at slower speed and with consequently increased power, by yieldingly compressing the clutch parts 20 and 21 into clutching engagement of the teeth 22 and 23 thereof, and by consequent sliding movement of cable 17 pinion 43 is urged out of mesh with gear 39. For limiting movement of the cable 17 in member 10, in clutch engaging direction, a ball 45 welded to the outer face of pinion 43 is engageable with an annular wall portion 46 of hand-grip 31 disposed oppositely to said outer face. Movement of the cable in the opposite, gear meshing direction, is limited by engagement of a reduced extension 47 of end portion 13 with the inner end of the sleeve 26 in work-turning part 24 (see Figure 2).

In use or operation of the improved wrench, as for loosening a tight nut, the work-turning part 24 first has a wrench socket of proper size (not shown) fitted on the squared end 25. Now with the socket engaged over the nut, the operator by grasping hand-grip 31 with one hand and handle 14 with the other, may turn the tool to rotate the work-turning part and said socket. Initially, loosening of the nut however, is accomplished with increased power at relatively slow speed, by applying sufficient axial pressure upon member 10 toward the work yieldingly to engage the clutch 18 (see Figure 5), thereby disengaging the gears 39 and 43 and operating the workturning part directly through member 10, as shown in Figures 4 and 5. As soon as the nut has been loosened,

it may be more quickly removed, by releasing said axial pressure on the member 16, allowing the spring 28 to disengage clutch 18 (see Figures 1 and 2), with consequent rearward movement of member and grip 31 with respect to the cable 17, which re-engages the gears 39 and 43 (see Figure 1) to drive the worloturning part at increased rotative speed, indirectly through rotation of cable 17.

Thus, there has been provided an improved two-speed wrench which accomplishes the objects of the invention, and which operates safely with a minimum of ex posed moving parts.

Referring to Figures 6 and 7, there is illustrated a modified form of hand-grip and change-speed mechanism, corresponding to the structure described above in connection with Figure 4. The modified change-speed mechanism is designed for use with other parts of the general form of the wrench shown in Figures 1 to 3, and hence like parts will be given like reference numerals unless otherwise noted.

The improved change-speed mechanism comprises a hand-grip having a cup-shaped part 51 defined by an inner wall 53 and an annular flange 52, extending angularly of a general plane of wall 53, said inner wall having a central boss 54 through which is rotatably received an axially extending straight portion 12a of the tubular member 10, previously described in connection with Figures 1 to 5. The hand grip 59 may be relatively rotatably retained on end portion 12a, as by means of a half of a conventional Washer 55 received in a slot 56 in the periphery of the boss 54, to have arcuate inner portions 57 of the washer received in an annular groove 58 in the straight portion 12a, and to embrace a reduced inner surface portion of the same. The half washer 55 is shown aflhced to the boss 54 by means of a pin 58, the arrangement being such that the hand-grip part 51 is relatively rotatable on portion 12a about the axis of the tool, but is not movable axially of portion 12a. A dome-shaped cap 59 may be removably afiixed to the otherwise open outer end of the cup-shaped part 51 to close the same.

Welded or otherwise non-rotatably affixed to a reduced outward extension 60 of tubular member 10 may he an L-shaped bracket 61, having an angular extension 61a in which a shaft 62 is journalled to be rotatable about an axis at right angles, to said axis of the tool. Also rotatable on said axis may be a bevel gear 63, non-rotatably affixed to solid extension 17a of an elongated metal sleeve 17b afiixed on the corresponding end 17c of the flexible cable 17, said sleeve being slidably and rotatably received in a bore 6% in the straight portion of end part 12a, including the extension 69 thereof. The gear 63 is meshed with a bevel gear 64 affixed on the inner end of shaft 62, which also has affixed to the outer end thereof a bevel gear 65, in turn meshing witha relatively larger bevel gear 66 of annular construction aflixed to the inner wall 52 of the hand-grip part 51.

The arrangement is such that operation of the tool is generally as previously described in connection with Figures 1 to 5, but with the structure of Figures 6 and 7 substituted for the structure best shown in Figure 4. Normally the clutch 18 is held yieldingly disengaged by the spring 28, as shown in Figure 2, so that when the operator turns the member 10 about the aforementioned axis of rotation of the tool the gear 63 is engaged with the gear 64, and the work-turning part 24 (Figure 2) is operated at relatively high speed as for threading a nut on a bolt. Conversely, when the operator wishes to turn the work at slower speed, but with greater power, he urges the hand-grip and member 10 inwardly to engage the clutch 18, thereby yieidingly shifting member 10 with respect to cable 17 to disengage gear 63 from gear 64. As a consequence, when the member is turned about said axis of rotation, as described for high speed operation, the bracket 61 is correspondingly turned about the same axis of rotation while the hand-grip is relatively non-rotatably gripped in the hand, whereby the small gear 65 in rolling around larger gear 66 turns the cable 17 at relatively slow speed, through the meshing gears 63 and 64. The use and operation of the tool is otherwise substantially as previously described in connection with Figures 1 to 5.

The modified structure of Figures 6 and 7 has the advantage of providing for positive and accurate movement of the shittable parts of the gear mechanism, from and toward driving connection of the releasably interengaging gears. The structure, moreover, provides im proved simple means by which the gear mechanism in the hand-grip 50 is easily reached for repair and maintenance purposes.

Other modifications of the invention may be resorted to without departing from the spirit thereof or from the scope of the appended claims.

What is claimed is:

l. A multiple speed device of the character described, comprising a member having a turning axis, means on said member for rotating the same about said axis, said member having a passageway therethrough, a hollow hand-grip rotatably mounted on an end of said member, an element slidably and rotatably received through said member passageway, said element having an extension thereof within said hollow hand-grip, a gear affixed on said hand grip in axially centered relation, a gear affixed on said extension, a holder afiixed on said member within said hand-grip to be rotatable with the member about said axis relative to the hand grip, drivingly connected gears rotatably mounted on said holder for meshing engagement with the respective gears on said extension and said hand-grip, means for slidably shifting said element in said member from and toward a position in which said gear on said extension is in meshing position for relatively high speed rotation of said element.

2. A multiple speed wrench of the type for operating a work-turning tool, comprising a member having a turning axis, means on said member for rotating the same about said axis, said member having a passageway therethrough, a clutch part axially shiftably mounted on said member and a clutch part fixed on said member to be engageable by the shiftable clutch part, work-turning means on said shiftable clutch part for attachment of a work-turning tool, a hollow hand-grip rotatably mounted on an end of said member, a flexible element slidably and rotatably received through said member passage way and having said shiftable clutch part secured to the same, said flexible element having an extension thereof presented within said hollow hand-grip, a gear aifixed on said hand-grip in axially centered relation, a gear aifixed on said extension, a holder atfixed on said member within said hand-grip to be rotatable with the member about said axis relative to the hand grip, drivingly connected gears rotatably mounted on said holder for meshing engagement with the respective gears on said extension and said hand-grip, said gear on said extension being shiftable with sliding movement of the element toward and from a meshing position with respect to its said respective gear, and resilient means normally yieldingly urging said element to a position in which said clutch parts are disengaged and said gear on said extension is in meshing position for relatively high speed r operation of said work-turning means through said ele ment, from an engaged position of said clutch parts in which the work-turning means is operated at relatively lower speed through direct driving connection with said member through said clutch parts.

3. A multiple speed wrench of the type for operating a work-turning tool, comprising a member having a turn ing axis, means on said member for rotating the same about said axis, said member having a passageway therethrough, a clutch part axially shiftably mounted on the tool end of said member and a clutch part fixed on said tool end to be engageable bv the shiftable clutch part, work-turning means on said shiftable clutch part for attachment of a work-turning tool. a hollow hand-grip rotatably mounted on the other end of said member, a flexible element slidably and rotatably received through said member passageway and having said shiftable clutch part secured to the corresponding tool end thereof, said flexible element having an extension thereof presented within said hollow hand-grip, a gear affixed on said hand-grip in axially centered relation, a gear afiixed on said extension, a holder afiixed on said member within said handgrip to be rotatable with the member about said axis relative to the hand grip, drivingly connected gears rotatably mounted on said holder for meshing engagement with the respective gears on said extension and said handgrip, said gear on said extension being shiftable with sliding movement of the element toward and from a meshing position with respect to its said respective gear, and resilient means normally yieldingly urging said element to a position in which said clutch parts are disengaged and said gear on said extension is in meshing position for relatively high speed operation of said workturning means through said element, from an engaged position of said clutch parts in which the work-turning means is operated at relatively lower speed through direct driving connection with said member through said clutch parts.

4. A multiple speed Wrench of the type for operating a work-turning tool, comprising a member having a turning axis, means on said member for rotating the same about said axis, said member having a passageway therethrough, a clutch part axially shiftably mounted on the tool end of said member and a clutch part fixed on said tool end to be engageable by the shiftable clutch part, work-turning means on said shiftable clutch part for attachment of a work-turning tool, a hollow hand-grip rotatably mounted on the other end of said member, a flexible element slidably and rotatably received through said member passageway and having said shiftable clutch part secured to the corresponding tool end thereof, said 'flexible element having an extension thereof within said hollow hand-grip, a gear of substantial size afiixed on said hand-grip in axially centered relation, a relatively smaller gear afiixed on said extension, a holder aflixed on said member within said hand-grip to be rotatable with the member about said axis relative to the hand grip, a shaft rotatably mounted on said holder, gears aflixed on said shaft for meshing engagement with the respective gears on said extension and said hand-grip, said gear on said extension being shiftable with sliding movement of the element toward and from a meshing position with respect to its said respective gear, and resilient means normally yieldingly urging said element to a position in which said clutch parts are disengaged and said gear on said extension is in meshing position for relatively high speed operation of said work-turning means through said element, from an engaged position of said clutch parts in which the work-turning means is operated at relatively lower speed through direct driving connection with said member through said clutch parts.

5. A multiple speed wrench of the type for operating a work-turning tool, comprising a curved tubular member having a central hand-grip portion and oppositely outward reversely bent offset end portions substantially on a common axis, said member having a passageway therethrough, clutch means on one offset end of said member including relatively movable clutch engaging parts, work-turning means on one said clutch part for attachment of a work-turning tool, a hollow hand-grip rotatably mounted on the other offset end of said member, a flexible element slidably and rotatably received through said member passageway and having said one clutch part secured to the corresponding end thereof, said flexible element having an extension thereof within said hollow hand-grip, a gear afiixed on said hand-grip in axially centered relation, a gear afiixed on said extension, a holder afiixed on said member within said hand-grip to be rotatable with the member about said axis relative to the hand grip, a shaft rotatably mounted on said holder, gears afi'ixed on said shaft for meshing engagement with the respective gears on said extension and said hand-grip, said gear on said extension being shiftable with sliding movement of the element toward and from a meshing position with respect to its said respective gear, and resilient means normally yieldingly urging said element to a position in which said clutch parts are disengaged and said gear on said extension is in meshing position for relatively high speed operation of said work-turning means through said element, from an engaged position of said clutch parts in which the work-turning means is operated at relatively lower speed through direct driving connection with said member through said clutch parts.

References Cited in the file of this patent UNITED STATES PATENTS 

